The short answer is yes, it's horses for courses - there is a fair amount of variability in both.
I like parlours because I tend to punt as a last minute decision, but my kinkiness (domme and T-girls) means planning ahead for indies also works for me.
I mostly use Manchester parlours when I'm looking for a spontaneous punt, and generally it ends up being cheaper, but you tend to need to spend £10/20 on extras for a good service, and there are parlours such as Boudoir Babes, where the girls take the piss and it ends up being more than an indie.
My current target list (mix of regulars and hot lists) is mixed about 50/50 between parlours and indies, with a slight skew to indies due to the T-girl thing.
At parlours you also build up a rapport with the receptionists who help, and see other girls in reception.
Tracy and Lauren on reception at Roses have been brilliant for me over the years, letting me know if a girl is suitable for me, and talking new ones through what I'm into so they're ready for me when I arrive.
Parlours are definitely better for 30 minute punts, but the girls you want will be specific days, whereas an indie can be available more frequently.
I'd recommend Roses, Temptations, The Lounge27, Abby at the Georgian, some times La Maison and Infinity.
I'd steer clear of Boudoir Babes.
Check the girls who are on for what you like.
e.g. I frequent a shity parlour in Leigh, purely because it's the only place I can see Martine.